Odds on, Obama will be returned as president

Over the past few months the opinion polls have swung this way and that in the US presidential election, from an initial Obama high to the present situation where, by most reasonable polls, a virtual tie in the popular vote is expected.

The peculiarities of the US electoral system can and occasionally do mean that even winning the popular vote is not enough to win the election, and it is also generally seen that Obama retains an edge there.

As of Thursday the RealClearPolitics poll of polls has the race tied. Opinion polls are fickle creatures — they are always interpretable with a margin of error that can range from 2%-5%; they are dependent on the sample being a representative sample of the likely population, and in an electorate which is as fractured as the US that is not easily guaranteed. They rely on people saying what is truly in their mind and not what they think the pollster wants to hear; and they are dependent on statistical adjustments to make the poll as close to the ideals above as the particular statistician in charge deems appropriate.